72 # ""v' o .:. :'þ ø.:. j' ..; A d.:.;.'ß- ..' 1>- ; /.:';t ..' '""" -w : :'<:.:,. / . ? /'^ J (I , l :. t j , ti "- ,.., l.: ...t . \! l \ t t, \ ( , i .,.. t, . ;. t '; , 't ,. ,.J 1', \ '<- 1 < ' 'r . {or ; 'I ' "'1' ..p . . i '-/ / ::, .: ..'v ".' ,f $. <>:/:':':' .' -\ ".:% --s. ... -:t .:':' .Ä' / l* / <.... l' . , -;. _.. ." ), X .": :/1 . ..,.. /,.. -T: . ^. ':. <-;' / /1'"/, .,.-:. . . SILK-ON THE DOUBLE! Our own blouse and skIrt masquerades as a dress or divides to conquer other separates The V-necked top with its bevy of ruffles is long enough to wear as an overblouse; the waltz-wide bias skirt has a back zipper, side seam pockets. Wide self sash wraps ' round the waist. Heavy pure silk crepe. Black 6-20 $150.00 (1.90 shippIng). Thrown over one shoulder-tha opulent shawl of black challis aglint WIth gold stripes. Self fringed edges. 4 feet square Black! gold $17.50 (1.10 shipping) N Y State residents add sales tax Check, M 0, American Express, Diners Club Vìsa/BankAmericard, Master Charge "UPSTAIRS" the Brownstone .ßoutique on the 22nd floor at 342 Madison Ave., Dept N3 New York, N.Y. 10173 Write or call for our FREE FALL BROCHURE Round-the-Clock Toll-Free 800-221-2468 In N.Y. State, Toll-Free 1-800-442-8422 In New York City call 953-1170 IrownçronE: snJDIO which is in a two-to-one resonance with Dione-that is, it orbits twice for every orbit of Dione-may be heated tidally by Saturn: Dione tends to make Enceladus' orbit elliptical, and the dif- fering stresses of Saturn's gravity may heat its interior. This would mean that its icy crust would remain thin. Meteoric impacts wouldn't crater it- they would puncture it. One impact puncturing Enceladus' crust every few thousand years would throw enough water into space to maintain the E ring. And if some of the water fell back onto Enceladus, that would ex- plain why the moon is so white. We'll have a better idea about all this after Voyager 2, which will be flying almost in tandem with Enceladus for a few hours, right over the terminator-the day-night line-where it's easy to spot any surface detail. Of course, we won't be able to look at Enceladus the whole time, but we should be able to take pictures of a good part of the surface. And our approach will be a lot closer-fifty-six thousand miles. V oy- ager l's closest approach was much farther out. I m st say I was happy when no surface details showed up in the pictures, because Cook and I had predicted that Enceladus would be smooth." I N the other interactive room, T 0- bias Owen was looking at various pictures of the limb, or edge, of Ti- tan's disc. Titan was back in the news, because at the press conference that morning the ultraviolet team had an- nounced the discovery of two distinct layers of haze in its upper atmosphere. Smith had been able to present further evidence of the layers: a picture of the limb of Titan, much enhanced, in ex- aggerated colors, by the processing lab, had brought out a thin blue layer of haze hovering above a second, thicker blue layer; below these two blue layers lay the far thicker aerosol layer, which gives Titan its brownish- yellow appearance. The color dif- ference between the aerosol layer and the thin hazes above might have to do with temperature as well as density, Smith had said. "There's a problem," Owen said, pushing some buttons on the interac- tive. "W e want to see if the two top layers we see really are the same as the ones the ultraviolet team has detected. The trouble is that their numbers in- dicate that their layers are a little higher up than ours. At some pOInt, we will have to tie both the imaging and the ultraviolet data in with the AUGUST 24, 1981 radio-occultation data, and perhaps that will sort things out." I asked Owen if the radio team had refined their data down to the surface of Titan yet. "They don't know," he said "They have got farther down now, to a level where the pressure is one and a half times the earth's at sea level, and the temperature is 92 0 Kelvin. If that 7J,Jas the surface, then the radius of Ti- tan would be 2,560 kilometres-about 1,590 miles-and its density 1.92 grams per cubic centimetre But they think they will go down a good deal farther." One thing he was sure of, he added, was that Titan had been de- throned as the largest satellite in the solar system; the level up to which the data had already been processed repre- sented a radius somewhat smaller than the 1,640 miles of the Jovian satellite Ganymede. T HE next day-Saturday, No- vember 15th-I asked Edward Stone, the chief scientist for Voyager, if he agreed with Smith that the analy- sis of the data had entered a new phase. He nodded. "Normally, a scientist might get some data and then have, say, six months to think over where he is in a problem, and what he wants to look for next, before he gets his next set of data," he said. "With Voyager, the time frame has been much faster. We've known right along that we would be getting totally new data in a matter of hours, and therefore we haven't wanted to waste time thinking about a problem-unless, of course, the idea popped right out at us. The mysterious B-ring spokes are a good example of that: they were black as we approached Saturn, and white as we moved away. We knew we were going to get new data from beyond the rings, and we didn't want to waste time working on the spokes until the infor- mation was all in. Right now, we're at the point where most of our informa-